Fig. 3.

Internal oligosaccharide and nonreducing end CS/DS from INS-1832/13 cells.A and B, heatmap summary of internal oligosaccharides (A) and nonreducing ends (B) after chondroitinase AC (ChAC, orange) and chondroitinase B (ChB, blue) depolymerizations. The intensities of the different structures were determined using an automated search routine, and the two structures with the highest intensities after each depolymerization are displayed in the boxes underneath each heatmap (ChAC, orange; ChB, blue). C, total intensities of internal oligosaccharides (left) and NREs (right) after ChAC (orange) and ChB (blue) depolymerizations (mean ± SD). D, HCD-MS² spectrum of the [M+DBA-3H]^2– precursor ion at m/z 562.6158 at NCE 70% corresponding to Δdp4S3, assigning the additional sulfate group to the internal IdoA residue. Mass accuracies of precursor and fragment ions are found in supplemental Tables S1 and S2. dp, degree of polymerization.